An elevator descends into a shaft at the rate of 3m/min. If the descent starts from 40m above the ground level, how long will it take to reach -20m?

Respuesta :

Answer:

20 m

Step-by-step explanation:

distance = 40 m + (20 m under)  = 60m

x min = 60 m

1 min = 3 m

x min = (60) (1) / 3

x = 20 min